Grain Bin Unloading Conveyor System

ABSTRACT

An unloading conveyor system for unloading grain through the floor of a grain bin. A removeable cover is vertically supported by the plurality of ribs to cover the span of the midpan to allow maintenance. The midpan comprises a plurality of slots and ledges to receive and support the ribs to allow easy installation and maintenance. A central pit having an internal portion and an access support wall also provides easy installation and maintenance. The first bearing mount, second bearing mount, and roller are all accessible for service through the internal portion of the central pit.

FIELD OF INVENTION

The present invention relates to unloading conveyor systems foragricultural grain storage bins, and, more particularly, to conveyorsmounted in a channel in the floor of a bin or under a raised floor of abin being fed by a series of radially spaced openings or wells formed inthe floor, through which grain is delivered to the conveyor by gravity,in collaboration with a sweep conveyor that rotates about a centralpivot point of the bin to direct residual grain into one or more of thewells in the floor.

BACKGROUND

Seed and grain are commonly stored in grain bins and related storagestructures. Grain storage structures—such as grain bins—commonly utilizea concrete foundation providing a foundation on which a series of formedsteel rings (i.e. corrugated cylindrical sections) are joined and extendupward to form a cylindrical tank. Many such grain bins have perforatedsteel floors supported on the concrete foundation and spaced above thefloor of the foundation, for purposes of passing air upwardly throughthe stored grain for aeration of the grain to control the drying andmoisture content of the grain, preserve the grain, and reduce loss.

Horizontal unloading augers have been principally used in the past toremove the grain from the bin. These augers are placed between theconcrete foundation and the perforated steel floor or in a trough formedin the foundation. The augers extend from the center of the bin throughthe side wall to several feet outside the bin for discharge into anothermass flow auger or conveyor for subsequent transport to market or otheruse. The unloading auger carries grain away from an enclosed metalframe—a well—at the center of the grain bin. The grain flows via gravitythrough the center well into the auger. The center well typically has amoveable slide gate which can be operated from outside the grain bin tocontrol grain flow through the well.

Eventually the bin empties to the point where no additional grain canflow under gravity into the center well, leaving residual grain on theouter edges of the floor of the grain bin extending from the center welland sloping upwards to the outer wall of the bin. The remaining grain,referred to as the residual grain, is considerable, rising from a fewinches near the center to as much as ten or twelve feet at the outerwall, for larger diameter bins. The valuable residual grain is commonlyremoved from the bin via a powered horizontal sweep auger. This poweredhorizontal sweep auger rests on the perforated floor and may be placedover the unloading auger prior to filling the grain bin. Commonly,additional secondary wells are placed over the unloading auger to removegrain from around the powered horizontal sweep auger so it is free ofthe residual grain pile prior to commencing its rotary “sweep”operation. Power to the sweep is either transferred from the unloadconveyor—as described in U.S. Pat. No. 7,544,031—or the sweep is poweredwith a dedicated electric motor, or equivalent power source. The sweepconveyor transfers power from the power source, through the auger orchain to turn an idler roller. The idler roller is coupled to a distaldrive wheel such that power is transferred from the conveyor to thedrive wheel. The driven wheel is mounted perpendicular to the length ofthe sweep conveyor and drives the sweep about the pivot point, like thehand of a clock.

Recent improvements have been made to grain bin unloading systems forpurposes of reducing damage to grain. This damage is related to theclearance fit and steel flighting used in conventional unloading augersystems. Belt conveyors fitted under the perforated grain bin floor inplace of auger unloading systems are now being employed to minimizedamage to high value seed, as well as to improve energy efficiency andreduce unload time.

The belt conveyor is positioned under the perforated metal grain binfloor and may employ additional intermediate wells for removal ofresidual grain to clear the region about the power sweep before it isactuated. The drive roller typically employs a bonded rubber coating toprovide sufficient traction to transmit power to the conveyor belt.

BRIEF DESCRIPTION

We recognized that removeable cover plates would allow maintenanceaccess to the belt without removing the belt from the conveyor system.These removeable cover plates span across the trough or gap in a raisedfloor system. The removeable cover plates must be reinforced to supportthe weight of the grain and the sweep conveyor. The removeable coverplates are vertically supported by a plurality of ribs that extend alongan axis perpendicular to the longitudinal axis of the horizontal binunload conveyor. The ribs incorporate a tab that is received into themidpan to maintain proper spacing of the ribs sufficient to support theremoveable cover plates.

We also recognized that providing an overlap flange on the removeablecover plates prevents grain from entering the midpan. The overlap flangecovers the raised bin floor and extends over the external ledge to covera portion of the raised bin floor to provide a seal. The overlap flangealso provides a convenient place for securing the cover to the returntrough.

We also recognized that ribs incorporating a rib end having a first ribsupport flange and a second rib support flange would prevent the ribsfrom falling over during the installation or maintenance. The rib endshave a first rib support flange and a second rib support flange thatextend parallel to the longitudinal axis of the horizontal bin unloadconveyor when the ribs are installed. This provides support to maintainthe ribs in a vertical orientation when the tab is received into the tabslot.

We also recognized that a removable midpan can support the conveyorduring transfer of the material from the bin. The removable midpan issuspended within the return trough and provides a separation between theoutgoing, full portion of the conveyor belt from the returning, emptyportion of the conveyor belt. The ribs span across the midpan to allowthe outgoing and full portion of the conveyor belt to pass underneaththe ribs. The rib tabs are inserted into respective tab slotsappropriately spaced apart longitudinally along the horizontal binunload conveyor.

In order to operate the well gates or the clutch for the sweep conveyordrive mechanism, a control rod extends longitudinally through thehorizontal bin unload conveyor. In order to accommodate the control rod,the ribs incorporate a notch in the exterior side of a rib end. Thenotch allows the control rod to move along the peripheral interiorportion of the midpan. The midpan is configured with various ledges tosupport the ribs and the control rod.

One limitation of current systems is the roller, ball bearing mounts,and clutch system are located internal of the bin at or near the centerwell of the grain bin. This makes maintenance on the rollers, ballbearing mounts, and clutch system exceedingly difficult. Existingsystems require the raised floor be removed in order to access thebearings and to remove the roller. We recognized that the roller, ballbearing mounts, and clutch system could be more easily maintained byproviding a side access portion to the center well. Additionally, asecond bearing mount is mounted to the interior of the center well. Inthis way, the service parts are accessible within the center well andcan be maintained without removing the raised floor. This access alsoallows the user to maintain the belt, such as splicing the belt, withoutremoving the belt from the horizontal bin unload conveyor and withoutremoving the raised floor.

We also recognized that longitudinal risers could be attached to thefloor of the return trough to prevent the return portion of the conveyorbelt from freezing or otherwise binding up on the bottom of the returntrough. It is common for grain bins to be unloaded in the winter, andany residual moisture may descend to the bottom of the return trough.This moisture may freeze, causing the belt to bind up. This can damagethe belt. By attaching risers that run along the longitudinal axis ofthe return trough, the belt is supported and does not make sufficientcontact with the return trough to bind up. The return portion of thebelt moves along the top of the risers.

We also recognized that a generally U-shaped backstop mounted adjacentto the roller at the end of the transition assembly can prevent grainfrom backflowing into the center well and the return trough. Beltconveyors are more susceptible to material interposed between the beltand the roller causing interference with the proper operation of thebelt conveyor. The backstop has a lower profile that matches the shapeof the bottom of the transition piece. The backstop has a central slotthat allows the belt to pass through. The edges of the backstop rise up,generally perpendicular to the edges of the belt. In this way, theopenings around the belt—other than directly above the belt surface—areminimized.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other features, aspects, and advantages of the presentdisclosure will become better understood with regard to the followingdescription, appended claims, and accompanying drawings where:

FIG. 1 shows a top perspective view of a bin unload belt conveyorextending from a center well, wherein the cover is mounted;

FIG. 2 shows a top side perspective view of the conveyor of FIG. 1,wherein a cover portion has been removed to show a plurality of ribsextending across a lateral portion of the midpan;

FIG. 3 shows an exploded view of the components of a portion of theconveyor of FIG. 1;

FIG. 4 shows a detailed side perspective view showing the relationshipbetween a rib and the midpan of the conveyor of FIG. 1;

FIG. 5 shows a top perspective view of the conveyor of FIG. 1 having thecover and several ribs removed;

FIG. 6 shows a detailed top side perspective view of the center well,having the cover removed to show the service access portion of theconveyor of FIG. 1;

FIG. 7 shows another top view of the center well and service accessportion of the conveyor of FIG. 1; and

FIG. 8 shows a higher perspective view of the center well and theservice access portion of the conveyor of FIG. 1.

DETAILED DESCRIPTION

FIG. 1 shows a portion of an unloading conveyor system having a binunload conveyor 10 capable of being installed in a grain bin. The binunload conveyor 10 is installed in the floor of a grain bin and extendsradially from the bin center to the peripheral bin wall. The bin unloadconveyor 10 is mounted in the floor of a grain bin. The bin unloadconveyor 10 may be mounted within a channel in the floor of a bin.Alternatively, the bin unload conveyor 10 may be mounted to a raisedfloor of a bin. The bin unload conveyor 10 is fed by a series ofradially spaced openings or wells formed in a floor. The grain isdelivered through these openings to the bin unload conveyor 10 bygravity. A sweep conveyor can complement the bin unload conveyor 10 bydirecting residual grain into one or more of the wells in the floor. Thesweep conveyor rotates about a central pivot point of the bin upon thefloor of the grain bin. For this reason, the top of the bin unloadconveyor 10 cannot interfere with the movement of the sweep conveyor.

In order to facilitate rapid access to the bin unload conveyor 10, acover 20 is removably mounted to cover the bin unload conveyor. Thecover 20 provides a top surface of the bin unload conveyor over whichthe sweep conveyor can travel over. The cover 20 is illustrated aspitched, having a central peak 24. The cover 20 prevents grain fromentering at points along the bin unload conveyor 10 other than throughthe gated pit areas.

FIG. 2 shows the internal components that support the bin unloadconveyor belt and provide vertical support for the cover 20. A midpan 30supports a portion of the conveyor belt 5 transporting the graintraveling out of the grain bin. The midpan 30 has a curvilinear bottomfor support the conveyor belt 5 and the load contained on the conveyorbelt. The midpan 30 has a first internal ledge 34 and a second internalledge 36 for supporting a plurality of ribs 50. The ribs 50 have a trussportion 52 that provides vertical support for the cover 20. Each rib 50has a rib end 54 that extends perpendicular from the truss portion 52 ofthe rib. The rib end 54 extends outwardly to form a first rib supportflange 56 and a second rib support flange 57. As illustrated, the firstrib support flange 56 and the second rib support flange 57 isillustrated as having a triangular shape, which prevents the rib 50 fromtipping over during the installation or removal of the cover 20. A notch60 is formed in an exterior side of the rib end 54, between the rib end54 and a rib foot 62. The rib foot 62 extends downwardly to the secondinternal ledge 36. The notch 60 allows a control rod 46 to pass throughalong the longitudinal axis of the bin unload conveyor 10. The controlrod 46 operates the clutch mechanism 242 for engaging the sweep driveassembly 240, which transfers power from the roller 228 to the sweepdrive sprocket 241.

Also shown in FIG. 2, the cover 20 has an overhang flange 22 thatextends beyond the first external ledge 32 and second external ledge 33of the midpan 30. The overhang flange 22 extends along the plane of thetop of the grain bin floor. The overhang flange 22 prevents grain, dust,and debris from entering the bin unload conveyor 10. The cover 20 may bemounted to the midpan 30 or the return trough 40 by passing a fastenerthrough the overhang flange 22. A cover 20 with an overhang flange 22 isadvantageous as the bin unload conveyor is operated while covered withgrain. In order to maintain operation of the bin unload conveyor, theflow of grain from the bin into the conveyor must be regulated—which isaccomplished by the gated wells.

The midpan 30 is received into a return trough 40, as shown in FIG. 3.The return trough 40 contains a portion of the conveyor belt 5 as itreturns empty after discharging the grain. The midpan 30 can beremovably mounted to the return trough 40 in order to allow the user toclean any debris that settled to the bottom of the return trough 40.Also shown in FIG. 3 is the central pit cover 221. The central pit cover221 covers the central pit maintenance area and belt return over theroller 228.

In order to support the cover 20 along the longitudinal length of thebin unload conveyor 10, the ribs 50 are longitudinally spaced apart at apredetermined interval, as shown in FIG. 4. In order to facilitate thisspacing—and to assist the maintenance and installation of the cover andribs—a plurality of rib slots 38 are provided on both lateral sides ofthe midpan 30. The rib slots 38 are shown on the third internal ledge 37and the first internal ledge 34. Each rib has a rib tab 58 on the firstrib end 54 and the second rib end 55. The rib tab 58 extends downwardlyand is received by the rib slot 38. The rib tab 58 also cooperates withthe first rib support flange 56 and the second rib support flange 57 tomaintain the rib in an upright position during installation andmaintenance.

Any residual grain, dust, or debris that accumulates around the belt andsettle into the midpan 30 can be removed to the return trough 40 throughthe cleanout aperture 31, as shown in FIG. 5. The cleanout aperture 31is disposed in the bottom of the midpan 30. This provides a passagewayfor any residual grain, dust, or debris to fall through to the returntrough 40 to prevent interference with the belt 5 movement.

One advantage of the current disclosure is that maintenance can beperformed while the conveyor belt 5 remains installed in the grain bin.FIG. 6 shows the internal portion of the central pit 220 with thecentral pit cover 221 removed. Removing the central pit cover 221 allowsthe user access to perform maintenance on the roller 228, first bearing234, second bearing 236, belt 5, clutch mechanism 242, sweep driveassembly 240, sweep drive sprocket 241, and belt tracking mechanism 238.Additional portions of the belts are accessible for maintenance byremoving the cover 20 and the midpan 30.

In order to access and replace the first bearing 234, the central pitcover 221 located above the roller 228 is removed. The bolts holding thefirst bearing 234 to the access support wall 224 are removed. The accesssupport wall 224 separates the belt return portion 223 of the centralpit 220 from the service access portion 222. Within the service accessportion 222, the sprocket connecting the sweep drive assembly 240 isdisconnected. The lock collar 235 is loosened. The roller is then freedto slide horizontally. The roller can then be pivoted to the side,providing sufficient clearance to remove the roller from the secondbearing 236. In order to remove the roller, the roller slot cover 232 isremoved. The roller slot 230 is a vertical slot in the access supportwall 224, which is illustrated in FIG. 8. Removing the roller slot cover232 from the roller slot 230 allows the user to insert or remove theroller 228 for maintenance or installation purposes. Removing the roller228 allows the user to access the second bearing 236. The second bearing236 is bolted to the surface of an interior wall of the central pit 220.By mounting the second bearing 236 to the interior surface, allmaintenance parts can be accessed without disturbing the floor of thegrain bin or removing the bin unload conveyor. All of this maintenancecan be accomplished with the bin unload conveyor maintained in place.

Other maintenance that can be required with belt conveyors is trackingof the belt 5. The user can access the tracking mechanism 238 within theservice access portion 222 of the central pit 220. The trackingmechanism is best shown in FIG. 7. The tracking mechanism is mounted tothe access support wall 224 on the service access portion 222 side.Adjusting the tracking mechanism 238 moves the roller 228 to properlydirect the belt and prevent the belt from rubbing against the sidewalls.

Additional maintenance that can be required with belt conveyors includebelt splicing to repair a section of the belt 5. By removing the cover20, the user can access the belt to perform belt splicing and other beltrepairs. Additionally, the use can access the belt in the return troughby removing the midpan.

Shown in the FIG. 1 is a portion of the bin unload conveyor 10 betweenthe central pit 220 and an intermediate pit 252. The central pit 220 isshown without the central pit cover 221 in order to reveal themechanisms accessible within the central pit. A central gate 140selective opens and closes the grain opening 145 for the central pit220. Grain is directed to the grain opening 145 via the sloped walls142, 143. The sloped walls 142, 143 are downwardly and inwardly slopedto direct the grain toward the grain opening 145. A plurality of bars144 prevent large chunks of grain and other large debris from enteringthe grain opening 145. Large chunks—frozen or otherwise boundtogether—can interfere with proper operation of the bin unload conveyor10.

Also shown in FIG. 2 is a sliding gate guide 158. The sliding gate guide158 supports the intermediate gate 252 when the gate is open above theintermediate well 250. The sliding gate guide 158 is mounted to the gatehousing 251. The gate housing 251 has an opening and slanted wallsleading into the opening to facilitate grain entering into the conveyorfor transporting grain out of the grain bin. The bin unloading systemcan have any number of intermediate wells, gates, and gate housingsdepending on the diameter of the grain bin 252. The sliding gate guide158 also prevents the gate from interfering with the belt 5 duringoperation of the bin unload conveyor 10. A similar sliding gate guide isprovided for the central gate 140 or for additional intermediate gates.

As shown in FIG. 1 is a backstop 226 for preventing grain frombackflowing into the belt return portion 223 of the central pit 220. Thelower portion of the backstop 226 matches the curvilinear shape of thebelt 5 as it progresses past the transition assembly 225. The belt 5 hasa flat orientation as the belt is wrapped about the roller 228. Thetransition assembly 225 guides the belt from the flat orientation to thecurvilinear orientation during material transfer as the belt passes fromthe center of the grain bin to the exterior of the grain bin through themidpan 30—the midpan having a complementary curvilinear cross section.As the grain flows through the central gate opening, the grain can beginto slide backwards into the tail of the conveyor—toward the belt returnportion 223 of the central pit 220—rather than be carried forward andout of the grain bin. The backstop 226 can comprise a rubber, ultra-highmolecular weight plastic, or steel. The backstop 226 is generallyU-shaped and is mounted at the downstream end of the transition assembly225. The backstop 226 has a first raised top portion, a second raisedtop portion, and a top central opening. The backstop 226 is mounted toan upstream wall of the central gate housing. The backstop 226 ismounted at a downstream portion of the transition assembly225—downstream referring to the movement path of the conveyor belt.

It is also contemplated that the pitch of the cover 20 may be flat. In aflat cover, the cover 20 would not have a central peak 24. The trussportion of the plurality of ribs would be formed with a flat top toaccommodate the flat cover 20.

We claim:
 1. An unloading conveyor system for a grain bin having a floorfor supporting grain within the grain bin, the floor having a channelextending from the center of the grain bin to a peripheral bin wall forunloading the grain, the unloading conveyor system comprising: a. acenter well disposed in the floor of the grain bin; b. a return troughdisposed within the channel and radially extending from the center wellthrough the peripheral bin wall; c. a midpan disposed within the returntrough, the midpan comprising: i. a first internal ledge; ii. a secondinternal ledge; iii. an external ledge; d. a plurality of ribslongitudinally spaced apart, each of the plurality of ribs comprises: i.a first rib end mounted upon the first internal ledge; ii. a second ribend mounted upon the second internal ledge; iii. a truss portion thatextends perpendicular to a longitudinal axis of the unloading conveyorsystem between the first rib end and the second rib end; and e. aremoveable cover mounted to cover the midpan and vertically supported bythe plurality of ribs.
 2. The unloading conveyor system of claim 1,wherein the plurality of ribs are removably mounted upon the midpan. 3.The unloading conveyor system of claim 1, wherein each of the pluralityof ribs further comprise: a. a rib support flange extending from the ribperpendicular to the truss portion.
 4. The unloading conveyor system ofclaim 3, further comprising: a. a control rod longitudinally extendingthrough the midpan, the control rod configured to activate a sweep driveassembly; and b. wherein each of the plurality of ribs further comprise:i. a notch in an exterior side of the second rib end through which thecontrol rod passes.
 5. The unloading conveyor system of claim 1, furthercomprising: a. a plurality of rib slots longitudinally spaced apart anddisposed along the first internal ledge and the second internal ledge.6. The unloading conveyor system of claim 5, wherein each of theplurality of ribs further comprise: a. a first rib tab extendingdownwardly from the first rib end and configured to be inserted in oneof the plurality of rib slots.
 7. The unloading conveyor system of claim1, wherein the removable cover further comprises: a. an overlap flangethat extends beyond the external ledge in an axis perpendicular to alongitudinal axis of the unloading conveyor system.
 8. The unloadingconveyor system of claim 7, wherein the removable cover furthercomprises: a. a central peak that is raised relative to the overlapflange.
 9. The unloading conveyor system of claim 1, wherein the centerwell further comprises: a. an access support wall configured to dividethe center well into a side access portion and a belt return portion.10. The unloading conveyor system of claim 9, further comprising: a. afirst roller bearing mount mounted to an interior surface of the beltreturn portion of the center well; and b. a second bearing mount mountedto an exterior of the belt return portion of the center well.
 11. Theunloading conveyor system of claim 1, wherein the midpan is removablymounted upon the return trough.
 12. The unloading conveyor system ofclaim 1, further comprising: a. a central pit; b. an access support walldividing the central pit into: i. a belt return portion; ii. a serviceaccess portion; c. a roller mounted within the belt return portion; andd. a vertical slot disposed within the access support wall wherein theroller may be pivotally removed through the vertical slot.
 13. Anunloading conveyor system for a grain bin having a floor for supportinggrain within the grain bin, the unloading conveyor system comprising: a.a return trough configured to be mounted to the floor of the grain binand extend radially from the center of the grain bin; b. a midpanremovably disposed within the return trough, the midpan having acurvilinear cross section; c. a plurality of ribs longitudinally spacedapart and removably mounted upon the midpan, each of the plurality ofribs comprises: i. a truss portion that extends perpendicular to alongitudinal axis of the unloading conveyor system; and d. a removeablecover removably mounted to cover the midpan and vertically supported bythe plurality of ribs.
 14. The unloading conveyor system of claim 13,further comprising: a. a central pit having an internal portion; b. anaccess support wall disposed within the central pit thereby dividing thecentral pit into: i. a belt return portion; ii. a service accessportion; c. a first bearing mount is mounted to the access support walland is configured to be accessible through the service access portion ofthe central pit; d. a second bearing mount is mounted to an interiorsurface of the belt return portion; e. a roller is mounted to the firstbearing mount and the second bearing mount; and f. wherein the firstbearing mount, second bearing mount, and roller are accessible forservice through the internal portion of the central pit.
 15. Theunloading conveyor system of claim 13, further comprising: a. aremovable cover disposed over the midpan; and b. a plurality of ribslongitudinally spaced apart and removably mounted to the midpan andconfigured to provide vertical support for the removable cover.
 16. Anunloading conveyor system for a grain bin having a floor for supportinggrain within the grain bin, the unloading conveyor system comprising: a.a central pit; b. an access support wall dividing the central pit into:i. a belt return portion; ii. a service access portion; c. a rollermounted within the belt return portion; and d. a vertical slot disposedwithin the access support wall wherein the roller may be pivotallyremoved through the vertical slot.
 17. The unloading conveyor system ofclaim 16 further comprising: a. a first bearing mount is mounted to theaccess support wall and is configured to be accessible through theservice access portion of the central pit; b. a second bearing mount ismounted to an interior surface of the belt return portion; and c. aroller is mounted to the first bearing mount and the second bearingmount.
 18. The unloading conveyor system of claim 17 further comprising:a. a transition assembly mounted within the belt return portion andconfigured to guide a belt into a curvilinear cross section; and b. abackstop having a curvilinear bottom edge complementary to thecurvilinear cross section of the belt, the backstop mounted at adownstream portion of the transition assembly.